2003 IMRC/IMSC issues


fullerrd

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Trying to fix my son's 2003 2.3L manual Ranger. Shows following codes:

P2004 Manifold Runner Control stuck open
P2008 Intake Manifold Runner Control circuit open
P0403 EGR System fault (fault in EGR solenoid circuit)
P0446 Evap emission system purge/ven solenoid circuit open
P0597 Thermostat heater control circuit open
P2195 Lack of heated oxygen sensor B1S1
P0141 HO2S12 heater condition
P0135 Ho2S11 heater condition

He started off by replacing the IMRC solenoid. All of the vacuum lines are good. I tested the IMRC actuator by pulling a vacuum on it and it does make noise and holds vacuum indicating the diaphragm is good. With the engine running, I can manually pull a vacuum on the IMRC and the engine idle smooths out and changes, indicating the butterflies are not stuck. Mechanically, I think the intake manifold and IMRC are sound.

I put a t-connector in the vacuum line with a guage between the IMRC solenoid and the IMRC actuator. I get no vacuum whatsoever going to the actuator, even though manifold is pulling 22 in. of Hg on the other side of the IMRC solenoid. No vacuum to the actuator regardless of RPM. I'm now thinking electrical.

I pulled the plug off the IMRC solenoid. Two wires, blue/red stripe and white/red stripe. The blue red shows continuity to ground with key off, key on, or engine running. The white red shows continuity to ground with the key on or the engine running, but not with the key off. Neither shows a voltage under any conditions. I pulled the main plug off the ECM on the firewall. the blue/red shows continuity to its other end and no ground fault. The main plug has two white/reds, neither of which shows continuity to the IMRC solenoid plug end. I would replace both with replacement wires, but I don't know which white/red is the correct one on the ECM plug.

My questions:

Should either of these wires show a voltage and under what conditions?
Can anyone provide a link to a good wiring diagram for all of the emission control systems and the ECM pinouts?

Most of the codes have in common the possibility of a bad circuit. I'm thinking this whole thing might be electrical. If anyone can make sense of this, please let me know.

Bob
 
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adsm08

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I didn't read the whole thing, just the code list.

You have a wiring issue, or a computer issue. Nobody has luck bad enough to cause all those codes separately.
 

fullerrd

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Finally got a wiring diagram from local ford dealer. All of these devices (EGR, H2OS, EVAP, IMRC, Thermostat) get their voltage off fuse 41 in the engine compartment, which was blown. While tracking down each component, I found that the front oxygen sensor plug was pulled apart. The front half of the plug was completely missing and the wires were shorting. Turns out that a year ago my son got the clutch replaced. Whoever did it obviously dropped the transmission without disconnecting the oxygen sensor.
 

Ruff b2

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I know this is an old post.. But Thank you much for posting this.
Was about to search wiring harness for broken/shorted wiring.

Found the same blown fuse and all is well.
 


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